Duke – and the rest of the KKK – backed Trump throughout the campaign – and last week, the Ku Klux Klan reportedly revealed plans to intimidate black voters on election day.

But who are the Ku Klux Klan? What do they believe and how do they carry out their views?

Here, we explain everything you need to know about the group.

What is the Ku Klux Klan?

In a nutshell, the Ku Klux Klan (or the KKK) is an extremist hate group. It claims to uphold Christian morals – but also promotes ideologies such including white supremacy, white nationalism and Nordicism (the belief that the Nordic race is supreme).

Historically, black Americans have been the KKK’s main target – but it has also targeted Jews, immigrants, LGBT people and even Catholics, until recently.

The group’s history since its formation in 1865 can be divided into three eras.

The first Klan, founded in Tennessee, was formed by former members of the Confederate army in around 1865. It was relatively short-lived – however, as secret vigilantes, the Klan carried out acts of terrorism such as the lynchings, arson, murders, tar-and-featherings, rapes and other violent attacks historically associated with the group. During the first era, these attacks were directed towards anyone who challenged white supremacy.

The second Klan, founded in Atlanta, Georgia in 1921, presented itself as a fraternal organisation – employing full-time recruiters. At its peak, it was present in every state in America – claiming to have at least 4 million members, operations in Canada, and even reportedly some recruiting activity in the UK.

However, the KKK’s popularity plummeted to only 30,000 members after a series of scandals. During this period, the Klan was particularly opposed to Catholic and Jewish immigration.

The third revival came in the 1960s in opposition to the civil rights movement, which in the Klan's eyes threatened segregation. The KKK name was used by a number of independent groups - many members of which were convicted of murders of civil rights workers. One of the KKK's most violent actions was the bombing of the 16th Street Baptist Church in Birmingham, Alabama in 1963 - an attack which killed four young girls.

What does the KKK do?

The KKK refers to its beliefs and practices as 'Klankraft'. Although they are a secretive group, there is some knowledge of its beliefs and practices - which are all, of course, based on their white supremacist views.

One of the most iconic symbols of the KKK is their white robes, which feature an conical mask. These were adopted by the first Klan, and were intended to add to the terror of their brutal attacks.

The 56-year-old, who is an antisemitic conspiracy theorist and Holocaust denier, is against what he believes to be the Jewish control of the Federal Reserve Bank, U.S. federal government and the media. He also believes in racial segregation.